<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			*{margin:0;padding:0;}
			li{list-style: none;text-align: center;line-height:30px;}
			a{text-decoration: none;color:white;}
			.firstnav{width:600px;}
			.firstli{width:100px;height:30px;background:red;float:left;}
			/*.secnav{width:400px;display:none;}/*重点*/*/
			.secli{width:100px;height:30px;background: red;}
			.firstli:hover .secnav{display:block;}
		</style>
	</head>
	<body>
		<div class="nav">
			<ul class="firstnav">
				<li class="firstli">
					<a href="">首页</a>
					<ul class="secnav">
						<li class="secli">
							<a href="">首页</a>
						</li>
						
						<li class="secli">
							<a href="">首页</a>
						</li>
						<li class="secli">
							<a href="">首页</a>
						</li>
						<li class="secli">
							<a href="">首页</a>
						</li>
					</ul>
				</li>			
				<li class="firstli">
					<a href="">首页</a>
				</li>
				<li class="firstli">
					<a href="">首页</a>
				</li>
				<li class="firstli">
					<a href="">首页</a>
				</li>
				<li class="firstli">
					<a href="">首页</a>
				</li>
				<li class="firstli">
					<a href="">首页</a>
				</li>
			</ul>			
		</div>
	</body>
</html>
